Double-stranded Deoxyribonucleic Acid Research Articles

Quantitative Study on a Simple Electrochemical dsDNA-Pregabalin Biosensor; Multi-Spectroscopic, Molecular Docking and Modelling Studies

Pregabalin (PGB) is a γ-aminobutyric acid (GABA) alkylated analog prescribed to treat neuropathic pain, fibromyalgia, and postherpetic neuralgia. Using analytical, spectroscopic methods and molecular docking and molecular dynamics (MD) simulations, a detailed experimental and theoretical investigation was conducted into the binding process and interactions between PGB and double-stranded fish sperm deoxyribonucleic acid (dsDNA). It was evident from the collected experimental results that PGB binds with ds-DNA. PGB attaches to dsDNA via minor groove binding, as demonstrated by the results of electrochemical studies, UV–Vis absorption spectroscopy, and replacement study with ethidium bromide and Hoechst-32588. PGB's binding constant (Kb) with dsDNA, as determined by the Benesi-Hildebrand plot, is 2.41×104 ± 0.30 at 298K. The fluorescence investigation indicates that PGB and dsDNA have a binding stoichiometry (n) of 1.21 ± 0.09. Molecular docking simulations were used in the research to computational determination of the interactions between PGB and dsDNA. The findings demonstrated that minor groove binding was the mechanism by which PGB interacted with dsDNA. Based on the electrochemically responsive PGB-dsDNA biosensor, we developed a technique for low-concentration detection of PGB utilizing differential pulse voltammetry (DPV). The voltammetric analysis of the peak current decrease in the deoxyadenosine oxidation signals resulting from the association between PGB and dsDNA enabled a sensitive estimation of PGB in pH 4.80 acetate buffer. The deoxyguanosine oxidation signals exhibited a linear relationship between 2 and 16μM PGB. The values for the limit of detection (LOD) and limit of quantitation (LOQ) were 0.57μM and 1.91μM, respectively.

Seroprevalence of cytomegalovirus (CMV) among pregnant women at a tertiary facility in southern Nigeria

Background: Cytomegalovirus (CMV) also called human cytomegalovirus (HCMV) or human herpesvirus-5 (HHV-5) is an encapsulated double-stranded deoxyribonucleic acid (DNA) virus. It is an opportunistic virus which often remains latent and only become symptomatic in immune-suppressed individuals such as pregnant women, HIV/AIDS patients and other immune weakening disease conditions. It is also estimated to have an 86% global sero-prevalence among reproductive women. Objectives: To determine the sero-prevalence of CMV infection, investigate the relationship between risk factors and CMV infection and to determine the relationship between obstetric characteristics and CMV infections among pregnant women. Method: A cross-sectional study among a cross-section of pregnant women receiving ante-natal care in the University of Port Harcourt Teaching Hospital from August 2022 to December 2022. A structured pro forma data sheet was used as interviewer-administered questionnaire by medical personnel to collect data from the study participants. 5ml of blood was collected from each participant and assessed for the presence of anti-CMV IgG using commercial Enzyme-linked Immunosorbent Assay (ELISA). The data were analyzed using Statistical Package for Social Sciences (SPSS) version 25. Descriptive statistics (mean, median, frequency percentage and standard deviation), Chi-square test and Fischer’s exact test were used appropriately. Results: Out of 101 respondents, only 24 (24%) were positive for CMV IgG, while 77 (76%) were negative. About 50% of the women were in their 3rd decade of life, while (3) were in the 4th decade of life. All the respondents were married and were Christians. Three quarters of the women [75(74.3%)] had tertiary education, 20 (19.8%) had secondary education, while 6 (5.9%) were Postgraduate students. Based on income, women with income < #50,000 (53.5%) were the most common. The relationship between demographic factors such as age, religion, income, educational level, employment status, marital status and CMV results were statistically insignificant. The relationship between obstetric characteristics and CMV results were not statistically significant, while risk factors for CMV and presence of CMV infection were not statistically significant as well. Conclusion: The 24% sero-prevalence for CMV at University of Port Harcourt Teaching Hospital was quite low; however it can be reduced to the barest minimum, by encouraging intensive awareness campaigns about the virus and providing free serum testing to all categories of the population, since CMV affects all ages.

A hitchhiker’s guide: estimates of microbial biomass and microbial gene abundance in soil

Information on microbial biomass carbon (MBC) is crucial to assess their stocks and role for plant nutrient release in soil. Next to fumigation-extraction, molecular methods are routinely used to estimate the contribution of fungi, bacteria, and archaea to the soil microbial community. However, more information on the links between these different indices would deepen the understanding of microbial processes. The current study is based on 11 datasets, which contain MBC and MBN data obtained by fumigation-extraction and information on bacterial, archaeal, and fungal gene abundance, totalling 765 data points from agricultural, forest, and rangeland soils. Some of these datasets additionally provide information on double-stranded deoxyribonucleic acid (dsDNA) and fungal ergosterol. MBC varied around the median of 206 µg g−1 soil. MBN followed with a median MB-C/N ratio of 4.1. Median microbial gene abundance declined from bacteria (96 × 108) to archaea (4.4 × 108) to fungi (1.8 × 108). The median ratio of MBC/dsDNA was 15.8 and that of bacteria/dsDNA was 5.8 × 108 µg−1. The relationships between MBC and dsDNA as well as between bacterial gene abundance and dsDNA were both negatively affected by soil pH and positively by clay content. The median ergosterol/MBC and fungi/ergosterol ratios were 0.20% and 4.7 (n × 108 µg−1), respectively. The relationship between fungal gene abundance and ergosterol was negatively affected by soil pH and clay content. Our study suggests that combining fumigation-extraction with molecular tools allows more precise insights on the physiological interactions of soil microorganisms with their surrounding environment.

Clinical and Immunological Profile of Systemic Lupus Erythematosus: A 5-year Retrospective Analysis from Northeast India.

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease with a wide range of clinical manifestations having considerable variation in clinical features that are influenced by ethnic, sociocultural, and geographical factors. This disease primarily affects young women aged between 18 and 35 years. The aim of this present study was to delineate the clinical manifestations and immunological patterns of SLE patients from the Northeastern (NE) region of India. The study was carried out in a tertiary care hospital from January 2016 to January 2021. Adult patients of age >18 years fulfilling systemic lupus international collaborating clinic criteria (SLICC) for classification of SLE were included in this study. Immunology such as antinuclear antibodies (ANA) and double-stranded deoxyribonucleic acid (dsDNA) were also performed followed by enzyme-linked immunosorbent assay (ELISA). Over a period of 5 years, 142 patients were recruited for the study, with an overall female-to-male ratio was 9.9:1, a median age at onset of 25 years (interquartile range age 21-32 years) and a mean disease duration was 15.25 months (range 2-60 months). Our study revealed that ANA was positive in 97.18% of patients while anti-dsDNA was positive in 78.68%, indicating that women from this region have higher positivity rates. Our findings support the notion that SLE is a multisystem disorder that predominantly affects young females, especially during the second and third decades of life. Hematological, mucocutaneous, and renal manifestations are common in our patients. Moreover, pulmonary, cardiovascular, and gastrointestinal (GI) manifestations were understudied in other cohorts, which is one of our study's strengths.

Highly selective detection of deoxyribonucleic acid in living cells using RecA-green fluorescent protein-single-stranded deoxyribonucleic acid filament fluorescence resonance energy transfer probe.

A fluorescence resonance energy transfer (FRET) method was developed for double-stranded deoxyribonucleic acid (dsDNA) detection in living cells using the RecA-GFP (green fluorescent protein) fusion protein filament. In brief, the thiol-modified single-stranded DNA (ssDNA) was attached to gold nanoparticles (AuNPs); on the contrary, the prepared RecA-GFP fusion protein interacted with ssDNA. Due to the FRET between AuNPs and RecA-GFP, fluorescence of RecA-GFP fusion protein was quenched. In the presence of homologous dsDNA, homologous recombination occurred to release RecA-GFP fusion protein. Thus, the fluorescence of RecA-GFP was recovered. The dsDNA concentration was detected using fluorescence intensity of RecA-GFP. Under optimal conditions, this method could detect dsDNA activity as low as 0.015 optical density (OD) Escherichia coli cells, with a wide linear range from 0.05 to 0.9 OD cells, and the regression equation was ΔF = 342.7c + 78.9, with a linear relationship coefficient of 0.9920. Therefore, it provided a promising approach for the selective detection of dsDNA in living cells for early clinical diagnosis of genetic diseases.

Different mobile counter ion types of magnetic ion-exchange resin coupling with ozonation treatment of the organic matter, antibiotic resistance genes, and pathogens in secondary effluent

Advanced treatment and reuse of secondary effluents (SE) from wastewater treatment plants is considered an effective method of alleviating the conflict between water supply and demand. However, the effective removal of organic matter, antibiotic resistance genes (ARGs), and pathogens in SE is key to ensure the safety of reclaimed water. In this study, the effectiveness of three types of magnetic ion-exchange resins (R-X, where X refers to –OH, –HCO3, and -Cl) coupled with ozonation (R + O) in reducing different types of carbon, pathogens, intracellular and extracellular antibiotic resistance genes (iARGs and eARGs), and microbial communities in SE was investigated. The results indicated that R-Cl was the best pre-treatment resin for ozonation. R-Cl + O (8 mL/L R-Cl adsorption for 30 min, followed by 15 min of 8 mg/L ozonation) achieved removal efficiencies of 49.7 %, 86.6 %, 99.9 %, 87.1 %, and 99.9 % for dissolved organic carbon, UV254, ΣiARGs, ΣeARGs, and Σpathogens, respectively. Ozonation was more effective than resin adsorption in the removal of ARGs, and R-Cl + O had the lowest rebounding potential for iARGs and pathogens. In addition, R-OH had the lowest removal efficiency of organic matter, iARGs, and pathogens compared to other types of resins owing to the electrostatic repulsion mechanism. Molecular dynamics simulations and average reduced density gradient analysis revealed that the quaternary amine sites of the resin had a positive surface electrostatic potential, which could firmly adsorb double-stranded deoxyribonucleic acid by electrostatic action. Ozonation effectively reduced the risk of ARGs and pathogens in the effluent of resin. The R + O treatment reduced organic matter, ARGs, and pathogens more effectively than single treatment, despite the different anionic groups of the resin.

A multifunctional fluorescent sensor for Ag+ and Hg2+ detection in seawater.

In order to detect Ag+ and Hg2+ in seawater, we explored a multifunctional fluorescence sensor. A multifunctional Ag+ and Hg2+ sensor was designed by using gold nanoparticles (AuNPs) as quenching agent, PicoGreen dye as fluorescent probe of base pairing double-stranded deoxyribonucleic acid (DNA), and combining the characteristics of Ag+ making C base mismatch and Hg2+ making T base mismatch. Meanwhile, the DNA logic gate was constructed by establishing logic circuit, truth table, and logic formula. The relevant performances of the sensor were investigated. The results revealed that the sensor can detect Ag+ in the range of 100 to 700nM with R2 = 0.98129, and its detection limit is 16.88nM (3σ/slope). The detection range of Hg2+is 100-900nM with R2 = 0.99725, and the detection limit is 5.59nM (3σ/slope). An AND-AND-NOR-AND molecular logic gate has been successfully designed. With the characteristics of high sensitivity, multifunction, and low cost, the recommended detection method has the potential to be applied to the detection of Ag+ and Hg2+ in seawater.

Serum 25(OH)D levels are associated with disease activity and renal involvement in initial-onset childhood systemic lupus erythematosus.

Vitamin D deficiency is common in patients with systemic lupus erythematosus (SLE) and may affect their disease activity and severity. This study aims to assess the vitamin D status in patients with initial-onset SLE during childhood and its association with the clinical and laboratory markers of disease activity. This is a retrospective study that includes 168 patients with initial-onset SLE during childhood and 109 healthy children as controls. Clinical and laboratory data were recorded. The area under the curve (AUC) method was used to evaluate the efficacy of double-stranded deoxyribonucleic acid (dsDNA), lower 25(OH)D and complement 3 (C3) alone and in combination to diagnose the presence of renal damage in children with SLE. Compared with the controls (25.53 ± 7.02 ng/ml), patients with initial-onset SLE during childhood have lower serum 25(OH)D levels (18.63 ± 5.32 ng/ml) (P < 0.05). Among patients with initial-onset SLE during childhood, SLEDAI-2K scores are significantly higher in the vitamin D insufficiency (median = 14.5) and vitamin D deficiency (median = 14.0) groups than in the vitamin D sufficiency group (median = 9.0) (P < 0.05). Patients with initial-onset SLE during childhood with lower 25(OH)D levels are more likely to have lupus nephritis (LN) and a higher SDI score (P < 0.05). Compared with patients with other types of LN (16.69 ± 3.90 ng/ml), patients with type V LN have lower levels of 25(OH)D (12.27 ± 3.53 ng/ml) (P < 0.05). The AUC was 0.803 when dsDNA antibody, 25(OH)D level and C3 were used in combination to diagnose LN in patients with SLE. Vitamin D deficiency and insufficiency are closely related to an increase in SLEDAI and SDI scores. Significant decrease in vitamin D level is a risk factor for LN.

Impact of temperature on the binding interaction between dsDNA and curcumin: An electrochemical study

In this study, we investigated the binding mode between double-stranded deoxyribonucleic acid (dsDNA) and curcumin (CU) using differential pulse voltammetry (DPV), UV–Vis spectroscopy, and molecular docking. By employing these techniques, we predicted the binding within the minor groove region of dsDNA and CU. Significantly, we employed electrochemistry, specifically cyclic voltammetry (CV), to explore the temperature effect on the dsDNA and CU binding. To the best of our knowledge, this is the first study to utilize electrochemical methods for investigating the temperature-dependent behavior of this binding interaction. Our findings revealed temperature-dependent variations in the binding constants: 2.42 × 103 M−1 at 25 °C, 4.26 × 103 M−1 at 30 °C, 5.44 × 103 M−1 at 35 °C, 6.29 × 103 M−1 at 40 °C, and 7.52 × 103 M−1 at 45 °C. Notably, the binding constant exhibited an increasing trend with elevated temperatures, indicating a temperature-dependent enhancement of the binding interaction.

Fabrication of Ag nanoparticles coated leonardite basalt ceramic membrane with improved antimicrobial properties for DNA cleavage, E. coli removal and antibiofilm effects

This study aimed to fabricate a novel, low-cost, and environmental-friendly ceramic membrane based on basalt and leonardite powders via press and sintering methods. The fabricated leonardite basalt ceramic membrane (LBCM) was coated with silver nanoparticles (AgNPs); to create an antibacterial surface. The capabilities of the bare and coated membranes were examined. In this context, water permeability reached 554 ± 2.61 and 447 ± 1.21 L/m2hbar for bare LBCM and AgNPs-coated LBCM, respectively. The fabricated membranes indicated 100% Escherichia coli (E. coli) removal efficiency at a transmembrane pressure of 0.5 bar. The solid surface antimicrobial activity of the LBCM and AgNPs-coated LBCM reached 26.38% and 100%, respectively. The LBCM and AgNPs-coated LBCM were analyzed for the in-vitro 2,2- diphenyl-1-picrylhydrazyl (DPPH) antioxidant. Accordingly, AgNPs-coated LBCM exhibited higher antioxidant activities than raw LBCM. The scavenging capacity reached 83.91% with AgNPs-coated LBCM, while only 58.95% was achieved with raw LBCM, indicating that AgNPs-coated LBCM was better than bare LBCM from an antioxidant activities perspective. AgNPs-coated LBCM had a deoxyribonucleic acid (DNA) cleavage activity (single-strand DNA cleavage activity at 50 mg/L and double-strand DNA cleavage activity at 100 and 200 mg/L). In contrast, the raw LBCM did not exhibit DNA cleavage activity at any concentration. AgNPs-coated LBCM showed higher antimicrobial activities (minimum inhibition concentrations (MICs) were 32 mg/L against Enterococcus faecalis (E. faecalis) and 64 mg/L against Staphylococcus aureus (S. aureus), Candida tropicalis (C. tropicalis), and Enterococcus hirae (E. hirae)). The biofilm inhibition of LBCM and AgNPs-coated LBCM powders was tested against S. aureus and Pseudomonas aeruginosa (P. aeruginosa). The maximum S. aureus inhabitations by LBCM and AgNP-coated LBCM were 60.34% and 99.12%, respectively. The inhabitation of P. aeruginosa increased from 52.38% before coating to 96.37% at the end of the coating process. Regarding E.coli microbial cell viability inhibition, LBCM powders and AgNPs-coated LBCM powders were found to inhibit E. coli growth by 68.35% and 100%, respectively.

Voltammetric studies on the interaction of ds-DNA with anti-cancer agents imatinib and erlotinib – Comparison of Au and Pt nanoparticle effects to drug-DNA complex formation

The interactions of imatinib (IMA) and erlotinib (ERL) with calf-thymus double-stranded deoxyribonucleic acid (ds-DNA) were studied by using monometallic (Au and Pt) and bimetallic (Au + Pt) nanoparticles modified DNA biosensors. The prepared electrochemical biosensors were designed to show the interaction between IMA (or ERL) and ds-DNA. The characterization of the prepared sensors was carried out by energy-dispersive X-ray spectroscopy (EDX). The influence of Au, Pt, and Au + Pt nanoparticles in the modified biosensor was investigated to elucidate the interaction between the anti-cancer drugs and ds-DNA. The interaction was realized based on the electrochemical oxidation signal (at about +0.80 V) of the guanine (dGu) base of ds-DNA by differential pulse voltammetry (DPV) in pH 4.8 acetate buffer. The effect of the nanoparticle’s concentration and interaction time of IMA (and ERL) with ds-DNA on the electrochemical response of dGu were optimized. The results showed that Au + Pt nanoparticles, especially for IMA, significantly affected the binding constant value of the drugs to ds-DNA. Interaction studies have also shown that the binding mode for IMA and ERL could be intercalation and groove binding and the binding constant values were found to be 68.3 × 106 M−1 and 27.3 × 107 M−1, respectively.

Lactobacillus plantarum CQPC02 intervenes in mouse lupus nephritis by regulating the NF-κB signaling pathway.

A strain of Lactobacillus plantarum CQPC02 (LP-CQPC02) isolated from naturally fermented kimchi was utilized in this investigation. In order to construct an animal model of lupus nephritis, pristane was used. We then used a kit to identify markers in mouse blood and tissues and a quantitative polymerase chain reaction (qPCR) to measure the expression of genes associated to nuclear factor kappa-B (NF-κB) in mouse kidney tissue. According to the results of the experiments, oral administration of LP-CQPC02 LP-CQPC02 may lessen the lupus nephritis-related rise in urine protein as well as the cytokine levels that were rising in the serum and renal tissues, including IL-6, IL-12, tumor necrosis factor alpha, and interferon. Additionally, in mice with nephritis, LP-CQPC02 can lower serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), and raise total protein (TP) and albumin (ALB) levels. In mice with nephritis, LP-CQPC02 can also reduce the positive rate of double-stranded deoxyribonucleic acid (dsDNA). Pathological sections were examined, and it was shown that LP-CQPC02 can lessen tissue damage such incomplete glomerular morphology and inflammatory infiltration brought on by nephritis. In the kidneys of mice with lupus nephritis, LP-CQPC02 can upregulate the expression of inhibitor of NF-κB (IκB-α), downregulate the expression of NF-κB, transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). Lactobacillus plantarum CQPC02 has been confirmed to have an intervention effect on nephritis in mice and has the potential as a probiotic.

Evolutionary mechanisms of virus variability

ABSTRACT. The evolutionary changes of viruses are primarily associated with the replication processes of viruses containing deoxyribonucleic and ribonucleic acids, which differ significantly. The genomes of most viruses containing ribonucleic acid are replicated with much less accuracy compared to the genomes of viruses containing deoxyribonucleic acid. Comparing the number of mutations in an infected cell reflects an inverse relationship between genome size and the frequency of mutations carried out by these two categories of viruses. Viruses with double-stranded deoxyribonucleic acid genomes have a low mutation rate compared to single-stranded genomes. The genome of viruses is not a stable unique structure, but rather an average, variable number of different amino acid sequences. It is in the virus population that a high mutation rate is maintained, and low variability is not beneficial for the preservation of viruses in nature. Some animal species may be intermediate hosts when new epidemic viruses appear. The introduction of non-viral nucleic acid into the viral genome can also contribute to the evolutionary changes of the virus, lead to the formation of defective genomes or to the emergence of hypervirulent strains. Viral genomes encode numerous molecules that modulate a wide range of protective immune mechanisms. The variability of viruses is also facilitated by the simultaneous integration of several proviral genomes into one cell, which activates the processes of recombination and genetic shift. An important evolutionary point may be the conversion of ribonucleic acid ribose into deoxyribose of deoxyribonucleic acid, which increases the stability of nucleic acids by more than 100 times. Horizontal gene transfer between viruses that infect different hosts is a central feature of the evolution of viruses containing ribonucleic acid. Eukaryote viruses with single-stranded deoxyribonucleic acid probably evolved from bacterial plasmids after they acquired capsid protein genes from the (+) ribonucleic acid chain of viruses. In addition to megaviruses and adenoviruses, polintons are likely precursors to bidnaviruses and virophages.

Effects of cryogenic condition and chemistry on the properties of synthetic and biopolymer cryogels

We discuss here the properties of seven different synthetic and biopolymer cryogels prepared under identical conditions, and how the cryogenic condition and chemistry affect their properties. The monomers used in the study are acrylamide (AAm), N, N-dimethylacrylamide (DMAA), sodium acrylate (NaAA), sodium methacrylate (NaMA), and 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS). Silk fibroin (SF), and double-stranded deoxyribonucleic acid (DNA) are selected as the biopolymers for the preparation of the cryogels. The nonionic monomers AAm and DMAA produce cryogels with the largest total pore volumes and average pore diameters while ionic cryogels exhibit a small pore volume due to the collapse of the pores during their drying. Moreover, SF cryogel has the most mechanically stable porous structure followed by AAm and DMAA cryogels. The experimental findings can be explained with the cryogenic conditions namely, the total ice volume in the cryogelation system and the true concentration of the monomers or polymers in the unfrozen domains after cryoconcentration, as determined from DSC measurements. The extent of cryoconcentration and hence the true concentration of the monomers or polymers regulate the mechanical stability of the cryogel pore walls.

Adsorption of melting deoxyribonucleic acid

The melting of a homopolymer double-stranded (ds) deoxyribonucleic acid (DNA) in the dilute limit is studied numerically in the presence of an attractive and impenetrable surface on a simple cubic lattice. The two strands of the DNA are modeled using two self-avoiding walks, capable of interacting at complementary sites, thereby mimicking the base pairing. The impenetrable surface is modeled by restricting the DNA configurations at the z≥0 plane, with attractive interactions for monomers at z = 0. Further, we consider two variants for z = 0 occupations by ds segments, where one or two surface interactions are counted. This consideration has significant consequences, to the extent of changing the stability of the bound phase in the adsorbed state. Interestingly, adsorption changes from critical to first-order with a modified exponent on coinciding with the melting transition. For simulations, we use the pruned and enriched Rosenbluth algorithm.

Absorption and escape kinetics of spherical biomolecules from fully porous particles utilized in size exclusion chromatography

The increasing demand for the characterization of large biomolecules such as monoclonal antibodies, double-stranded deoxyribonucleic acid (dsDNA), and virus-like particles (VLPs) is raising fundamental questions pertaining to their absorption (ingress) and escape (egress) kinetics from fully porous particles. The exact expression of their concentration profiles is derived as a function of time and radial position across a single sub-3 μm Bridge-Ethylene-Hybrid (BEHTM) Particle present in size exclusion chromatography (SEC) columns. The boundary condition at the external surface area of the particle is a rectangular concentration profile mimicking the passage of the chromatographic zone. Four different BEH Particles were considered in the calculations depending on the molecular size of the analyte: 2.0 μm 100 Å BEH Particles for small molecules, 2.0 μm 200 Å BEH Particles for monoclonal antibodies, 2.0 μm 300 Å BEH Particles for dsDNA (100 base pairs), and 2.5 μm 900 Å BEH Particles for virus-like particles (VLPs).The calculated concentration profiles of small molecules and monoclonal antibodies confirm that all BEH Particles present in the column reach quasi-instantaneously thermodynamic equilibrium with the bulk mobile phase during the passage of the chromatographic band. This is no longer the case for larger biomolecules such as dsDNA or VLPs, especially when the SEC particle is located near the column inlet and for high velocities. The kinetics of biomolecule egress is slower than its kinetics of ingress leading to pronounced peak tailing. The mean concentration of the largest biomolecules in the SEC particles remains always smaller than the maximum bulk concentration. This persistent and transient intra-particle diffusion regime has direct implications on the theoretical expressions of the observed retention factors and plate heights. Classical theories of chromatography assume uniform spatial distribution of the analyte in the particle volume: this hypothesis is not verified for the largest biomolecules. These results imply that non-porous particles or monolithic structures are the most promising stationary phases for the separation and purification of the largest biomolecules in life science.

On the interactions involving serine proteases obtained from Monacrosporium thaumasium (Ascomycota: Orbiliomycetes) and deoxyribonucleic acid (DNA): biological macromolecules in action

The use of force spectroscopy approaches performed with optical tweezers can be very useful in determining the binding modes and the physical chemistry of DNA interactions with ligands, from small drugs to proteins. Helminthophagous fungi, on the other hand, have important enzyme secretion mechanisms for various purposes, and the interactions between such enzymes and nucleic acids are very poorly studied. Therefore, the main goal of the present work was to investigate, at the molecular level, the mechanisms of interaction between fungal serine proteases and the double-stranded (ds) DNA molecule. Experimental assays performed with this single molecule technique consist in exposing different concentrations of the protease of this fungus to dsDNA until saturation while monitoring the changes on the mechanical properties of the macromolecular complexes formed, from where the physical chemistry of the interaction can be deduced. It was found that the protease binds strongly to the double-helix, forming aggregates and changing the persistence length of the DNA molecule. The present work thus allowed us to infer information at the molecular level on the pathogenicity of these proteins, an important class of biological macromolecules, when applied to a target specimen.

Current Advances in Nanotechnology for the Next Generation of Sequencing (NGS).

This communication aims at discussing strategies based on developments from nanotechnology focused on the next generation of sequencing (NGS). In this regard, it should be noted that even in the advanced current situation of many techniques and methods accompanied with developments of technology, there are still existing challenges and needs focused on real samples and low concentrations of genomic materials. The approaches discussed/described adopt spectroscopical techniques and new optical setups. PCR bases are introduced to understand the role of non-covalent interactions by discussing about Nobel prizes related to genomic material detection. The review also discusses colorimetric methods, polymeric transducers, fluorescence detection methods, enhanced plasmonic techniques such as metal-enhanced fluorescence (MEF), semiconductors, and developments in metamaterials. In addition, nano-optics, challenges linked to signal transductions, and how the limitations reported in each technique could be overcome are considered in real samples. Accordingly, this study shows developments where optical active nanoplatforms generate signal detection and transduction with enhanced performances and, in many cases, enhanced signaling from single double-stranded deoxyribonucleic acid (DNA) interactions. Future perspectives on miniaturized instrumentation, chips, and devices aimed at detecting genomic material are analyzed. However, the main concept in this report derives from gained insights into nanochemistry and nano-optics. Such concepts could be incorporated into other higher-sized substrates and experimental and optical setups.

The role of different viral biomarkers on the management of chronic hepatitis B.

Chronic hepatitis B infection is a major public health challenge. With the advancement in technology, various components of the viral cycle can now be measured in the blood to assess viral activity. In this review article, we summarize the relevant data of how antiviral therapies impact viral biomarkers, and discuss their potential implications. Viral nucleic acids including hepatitis B virus (HBV) double-stranded deoxy-ribonucleic acid (DNA) and to a lesser extent, pre-genomic RNA, are readily suppressed by nucleos(t)ide analogues (NUCs). The primary role of these markers include risk prediction for hepatocellular carcinoma (HCC) and risk stratification for partial cure, defined as off-therapy virological control, or functional cure, defined as hepatitis B surface antigen (HBsAg) seroclearance plus undetectable serum HBV DNA for ≥6 months. Viral translational products including hepatitis e antigen, quantitative HBsAg and hepatitis B core-related antigen can be reduced by NUCs and pegylated interferon a. They are important in defining disease phase, delineating treatment endpoints, and predicting clinical outcomes including HCC risk and partial/ functional cure. As the primary outcome of phase III trials in chronic hepatitis B is set as HBsAg seroclearance, appropriate viral biomarkers can potentially inform the efficacy of novel compounds. Early viral biomarker response can help with prioritization of subjects into clinical trials. However, standardization and validation studies would be crucial before viral biomarkers can be broadly implemented in clinical use.

Development of the DNA-based voltammetric biosensor for detection of vincristine as anticancer drug.

In the article presented herein, a deoxyribonucleic acid (DNA) biosensor is introduced for Vincristine determination in pharmaceutical preparations based on the modification of screen printed electrode (SPE) with double-stranded DNA (ds-DNA), polypyrrole (PP), peony-like CuO:Tb3+ nanostructure (P-L CuO:Tb3+ NS). The developed sensor indicated a wide linear response to Vincristine concentration ranged from 1.0 nM to 400.0μM with a limit of detection as low as .21nM. The intercalation of Vincristine with DNA guanine led to the response. The optimized parameters for the biosensor performance were ds-DNA/Vincristine interaction time, DNA concentration and type of buffer solution. The docking investigation confirm the minor groove interaction between guanine base at surface of or ds-DNA/PP/P-L CuO:Tb3+ NS/SPE and Vincristine. The proposed sensor could successfully determine Vincristine in Vincristine injections and biological fluids, with acceptable obtains.